// Copyright (c) 1999-2004 Brian Wellington (bwelling@xbill.org)

package org.xbill.DNS;

import java.util.*;

/**
 * Boolean options:<BR>
 * bindttl - Print TTLs in BIND format<BR>
 * multiline - Print records in multiline format<BR>
 * noprintin - Don't print the class of a record if it's IN<BR>
 * verbose - Turn on general debugging statements<BR>
 * verbosemsg - Print all messages sent or received by SimpleResolver<BR>
 * verbosecompression - Print messages related to name compression<BR>
 * verbosesec - Print messages related to signature verification<BR>
 * verbosecache - Print messages related to cache lookups<BR>
 * <BR>
 * Valued options:<BR>
 * tsigfudge=n - Sets the default TSIG fudge value (in seconds)<BR>
 * sig0validity=n - Sets the default SIG(0) validity period (in seconds)<BR>
 * 
 * @author Brian Wellington
 */

public final class Options {

	private static Map table;

	static {
		try {
			refresh();
		} catch (SecurityException e) {
		}
	}

	private Options() {
	}

	public static void refresh() {
		String s = System.getProperty("dnsjava.options");
		if (s != null) {
			StringTokenizer st = new StringTokenizer(s, ",");
			while (st.hasMoreTokens()) {
				String token = st.nextToken();
				int index = token.indexOf('=');
				if (index == -1)
					set(token);
				else {
					String option = token.substring(0, index);
					String value = token.substring(index + 1);
					set(option, value);
				}
			}
		}
	}

	/** Clears all defined options */
	public static void clear() {
		table = null;
	}

	/** Sets an option to "true" */
	public static void set(String option) {
		if (table == null)
			table = new HashMap();
		table.put(option.toLowerCase(), "true");
	}

	/** Sets an option to the the supplied value */
	public static void set(String option, String value) {
		if (table == null)
			table = new HashMap();
		table.put(option.toLowerCase(), value.toLowerCase());
	}

	/** Removes an option */
	public static void unset(String option) {
		if (table == null)
			return;
		table.remove(option.toLowerCase());
	}

	/** Checks if an option is defined */
	public static boolean check(String option) {
		if (table == null)
			return false;
		return (table.get(option.toLowerCase()) != null);
	}

	/** Returns the value of an option */
	public static String value(String option) {
		if (table == null)
			return null;
		return ((String) table.get(option.toLowerCase()));
	}

	/**
	 * Returns the value of an option as an integer, or -1 if not defined.
	 */
	public static int intValue(String option) {
		String s = value(option);
		if (s != null) {
			try {
				int val = Integer.parseInt(s);
				if (val > 0)
					return (val);
			} catch (NumberFormatException e) {
			}
		}
		return (-1);
	}

}
